1. Field of the Invention
This invention relates to improved valve constructions and particularly, to a sealing gasket that has so-called beam strength as utilized in a valve construction. One phase of the invention deals with a sealing element for fluid control usage that will have an improved resistance to position displacement and that will simplify valve construction and operation. Another phase relates to improved valve constructions for utilizing a resilient gasket constructed in accordance with the invention.
2. Description of the Prior Art
Heretofore, it has been customary in rotary and other valve applications to utilize so-called resilient O-ring gaskets. A so-called slot type of valve utilizes such a ring gasket in an inset position about a segment of its hemispherical or circular shape for sealing-off direct flow between inlet and outlet portions of a housing by, for example, rotating a back-up or control body which supports the gasket. There is a tendency for fluid pressure, and particularly higher fluid pressures, to elongate the gasket, since the material is relatively incompressible, and to thus force a portion of the gasket out of its seating groove or slot. In such a free sealing O-ring type of utilization, pressure elongation of the gasket causes it to bulge into the port area to not only effect a poor sealing operation, but primarily, to expose a portion of the ring such that it will be damaged in the rotation of the valve body, as by tearing. The replacement of the gasket then becomes essential. I have found that in this type of installation the difficulty arises from the fact that the gasket does not have beam strength sufficient to resist deformation and stay in position in its sealing groove.